Improvement in carbon-telephones



- BEST QGW T. A. Eblso-N. Carbon Telephone.

No 222,390. Patented Dec.9,1879.

UNITED ST TE PATENT FFIGE}.

THOMAS A. EDISON, OF MEN Lo PARK, NEW JERSEY, ASSIGNOR T0 wns'rnnn 1 J UNION TELEGRAPH COMPANY, or new YORK, n. Y.

IIMPROVEM EMT IN CARBON-TELEPHONES.

I Specification forming part of Letters Patent No. 222,390, dated Drccmbcr 9, P379; application filed November 11, 1 87B.

To all trhoin ztmay concern:

be it known that I. Tnomms ALVA Emson,

ot .\lonlo Park, in the county of Middlescx y andbtate of Sew Jersey, have invented an lm 'n'm'cznent' in Telephones, of which'the following is a. specification.

Thisinvcntion 1 term the micro-telephone,

' in consequence of the same responding to. ininute vibrations oi the instrument itself, transmitted to it by anysoiid body or of the atmosphere, and in so doingtransinitting electric pulsations toa distance, where they can be re ccivcdfby an ordinary telephone.

In the drawings, Figure 1 is nsectioncf the instrument, and Fig. 2 is a. plan of the some.

The box A is of a suitable size and shape for holding the apparatus, and for acting as a resonant case, one side thereof being open. -'l 'his casecon veys to the apparatus any vibrations or disturbance resulting from the soundvibrations of the atmosphere or from the vibration oi' thc-solid material upon which the box rests. I

In the box A is an opening, preferably round, in which is the diaphragm p, :"nd upon this diaphragm is apiece of compressed finelydividcd conducting material, such as carbon, n. A second piece of carbon or similar material, on, is secured to alcrer, c, the fulcrum or pivot of which is at a.

A lever-arm, h, and movable weight i may be employed to' balance the lever c and parts connected therewith, and the dclicatespring e'nnd ndjusting-spimlle f serve to increase or decrease the pressure of the buttons in 1: upon each other.

; The-pinto k,-ot'. li ht material, such as mice,

is connected with t e lever c, and this is within and protected by n funnel or mouth-piece, B, upon the box A.

It is now to be understood that the slightest vibration .or'j'ar given .to the nppnrntus, such as that resulting from walking ut o-room,

or from the articulate speech or Bound-vibrations, vary the pressure of m "upon each other,

and in so doing the electric condition of a circuit passing through 11- m c and wires 3 4 is varied, and a corresponding response. occurs in at distant receiving-telephone. The finelydivided carbon or other material between I: and 2 thus becomes a circuit-regulator, that acts to vary the resistanecin proportion to the vibration of the parts.

This transmitter is either included in .1 short circuit containing a receivingiclephone and' 1. The combination, with n resonant case or support, of the carbon or similar mnteriuhthe lever c.'disk k, and circuitc nnections. substantially as set forth.

2. Thc'combination of two movingplates or dinphragms, p and-k, with finely divided carbon or similar material intervening, and the circuit-connections passing through the some, substantially aseet forth.

8. The combination, with a resonant case, of two diuphrngms or plates, 1) and k, upon which sound or other vibrations o crate, and a circuit-regulator of fiuely-divi ed carbon or other material placed between such, plates k nndp and the circuit-connections, substantially no set forth.

Signed by me this 8th day of November, A. D. 1 78.

THOMAS A. EDISON. 'Witncaces:

a. L. GRIFFIN, Clue. BATOHELOB'. 

